(1) Field of the Invention
This invention relates to a method for the formation of capacitors comprising a polysilicon first capacitor plate, polysilicon oxide dielectric, and a metal second capacitor plate which improves uniformity of capacitance and avoids device damage. More particularly the invention relates to conditioning the polysilicon first capacitor plate by forming a thin layer of polysilicon oxide on the polysilicon followed by removal of the polysilicon oxide using a buffered oxide etch or a dry anisotropic etch.
(2) Description of the Related Art
U.S. Pat. No. 5,434,098 to Chang and U.S. Pat. No. 5,500,387 to Tung et al. describe processes using the formation of polysilicon oxide over polysilicon but do not describe the method of preconditioning the polysilicon surface described in this Patent Application.
This Patent Application describes a method of forming a polysilicon oxide dielectric between a polysilicon first capacitor plate and a metal second capacitor plate using preconditioning of the surface of the polysilicon first capacitor plate to achieve very uniform and well controlled polysilicon oxide formation.